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[commit, 6.0] Add frame_unwind_address_in_block
- From: Andrew Cagney <ac131313 at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Fri, 11 Jul 2003 10:50:53 -0400
- Subject: [commit, 6.0] Add frame_unwind_address_in_block
Hello,
This patch adds the function pair:
frame_unwind_address_in_block
get_frame_address_in_block
as successors to:
frame_address_in_block
The new methods are more correct (they handle dummy as well as sigtramp
frames) and follow a consistent nameing schema.
The expectation is that frame sniffers will use
frame_unwind_address_in_block as a way of obtaining a PC that falls
within the function.
A follow on patch will switch the mainline to get_frame_address_in_block
while the 6.0 branch will be left as-is.
committed to 6.0 and the mainline
Andrew
2003-07-11 Andrew Cagney <cagney@redhat.com>
* frame.h (get_frame_address_in_block): Declare.
(frame_unwind_address_in_block): Declare.
* frame.c (frame_unwind_address_in_block): New function.
(get_frame_address_in_block): New function.
Index: frame.c
===================================================================
RCS file: /cvs/src/src/gdb/frame.c,v
retrieving revision 1.130
diff -u -r1.130 frame.c
--- frame.c 7 Jul 2003 20:07:12 -0000 1.130
+++ frame.c 11 Jul 2003 14:42:37 -0000
@@ -2006,6 +2006,33 @@
return frame_pc_unwind (frame->next);
}
+/* Return an address of that falls within the frame's code block. */
+
+CORE_ADDR
+frame_unwind_address_in_block (struct frame_info *next_frame)
+{
+ /* A draft address. */
+ CORE_ADDR pc = frame_pc_unwind (next_frame);
+
+ /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
+ and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
+ frame's PC ends up pointing at the instruction fallowing the
+ "call". Adjust that PC value so that it falls on the call
+ instruction (which, hopefully, falls within THIS frame's code
+ block. So far it's proved to be a very good approximation. See
+ get_frame_type for why ->type can't be used. */
+ if (next_frame->level >= 0
+ && get_frame_type (next_frame) == NORMAL_FRAME)
+ --pc;
+ return pc;
+}
+
+CORE_ADDR
+get_frame_address_in_block (struct frame_info *this_frame)
+{
+ return frame_unwind_address_in_block (this_frame->next);
+}
+
static int
pc_notcurrent (struct frame_info *frame)
{
Index: frame.h
===================================================================
RCS file: /cvs/src/src/gdb/frame.h,v
retrieving revision 1.104
diff -u -r1.104 frame.h
--- frame.h 7 Jul 2003 14:36:58 -0000 1.104
+++ frame.h 11 Jul 2003 14:42:37 -0000
@@ -214,6 +214,22 @@
This replaced: frame->pc; */
extern CORE_ADDR get_frame_pc (struct frame_info *);
+/* An address (not necessarily alligned to an instruction boundary)
+ that falls within THIS frame's code block.
+
+ When a function call is the last statement in a block, the return
+ address for the call may land at the start of the next block.
+ Similarly, if a no-return function call is the last statement in
+ the function, the return address may end up pointing beyond the
+ function, and possibly at the start of the next function.
+
+ These methods make an allowance for this. For call frames, this
+ function returns the frame's PC-1 which "should" be an address in
+ the frame's block. */
+
+extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
+extern CORE_ADDR frame_unwind_address_in_block (struct frame_info *next_frame);
+
/* The frame's inner-most bound. AKA the stack-pointer. Confusingly
known as top-of-stack. */
@@ -526,6 +542,8 @@
extern struct symbol *get_frame_function (struct frame_info *);
+/* DEPRECATED: Replaced by tye pair get_frame_address_in_block and
+ frame_unwind_address_in_block. */
extern CORE_ADDR frame_address_in_block (struct frame_info *);
extern CORE_ADDR get_pc_function_start (CORE_ADDR);